The invention relates to a texturing apparatus for false twist texturing a yarn of the general type is disclosed in EP 0 853 150.
In the known texturing apparatus, a supplied flat yarn is textured by a false twist process. To this end, a false twist that a false twist unit produces in the yarn, is set by a heat treatment and a subsequent cooling. For cooling the false twisted yarn, a cooling tube is used, along the surface of which the yarn advances in spiral form. To change the cooling surface on the surface of the cooling tube as a function of the yarn type, the known texturing apparatus possesses a plurality of movable yarn guides, which change the slope of the spiral cooling zone on the circumference of the cooling tube. The yarn path that forms on the circumference of the cooling tube is called cooling zone. To avoid a too intensive cooling in the case of yarns with a low denier, a very flat angle of slope of the spiral cooling zone is adjusted on the circumference of the cooling tube. However, this changes at the same time the degree of the looping on the cooling tube. With that, the problem arises that it is impossible to adequately decrease in the cooling zone the highly dynamic twist oscillations, which are generated in the yarn by the false twist unit, and which propagate with the false twist against the advancing yarn. Thus, the twist oscillations propagate in the yarn as far back as the heating zone, and lead to an unstable yarn path that negatively affects the heat treatment.
It is an object of the invention to improve a standard texturing apparatus of the initially described type such that it permits influencing the cooling effect on the cooling tube without significantly changing the spiral cooling zone.